The ecology of land and sea are directly connected by rivers feeding marine deltas. Sediment runoff moving down a river eventurally ends up in the sea. The river flows of the Nile, Yangtze, and Mississippi have told much about history, civilization, and ecology for millennia.

Polar rivers in the Arctic are especially helpful to observe climate change in 'real time'. Landscape-wide soils long frozen (permafrost) is now melting and the runoff deposited into the Arctic Ocean. A new study measured change to the Yukon River over more than 30 years using water chemistry data. According to the report:

"the Yukon region hasexperienced a warming climate over the last century that has altered air temperature, precipitation, and permafrost. Using a water chemistry database from 1982-2014 for the Yukon River and its major tributary, the Tanana River significant increases of dissolved calcium (Ca), magnesium (Mg), and sodium (Na) were found in both rivers. Additionally, sulfates (SO4) and phosphorus (P) increased in the Yukon River.

The authors of the study concluded: "the thawing permafrost enables the release of more greenhouse gases to the atmosphere and also allows much more mineral-laden and nutrient-rich water to be transported to rivers, groundwater, and eventually the Arctic Ocean.”

Nutrients like calcium, magnesium, and phosphorus are essential for plant growth and when abundant in oceans can allow for the the spread of phytoplankton blooms. A video on permafrost shows the consequences of melting on cities, landscapes, and regional ecology.

The changes underway to the Arctic Ocean ecology are just beginning to be quantified.